After a disastrous failed hand-over from a independent Syrian liberation army unit, of the terrorist, "Omair Idrisi", Sergeant Daniel "Mac" Macallister, is imprisoned facing a court marshal for hitting his superior officer. Because of the failed hand-over mission, Col. Adeena Donovan, MI6, re-establish the disbanded "Section 20" unit. Mac, is offered a chance to join this new unit. He is quickly set on mission to recruit "Sergeant Samuel Wyatt", a deniable American operator, in captivity by General Farid. During the rescue/recruit mission, other new "Section 20" operators shows their value as members of the new team. The team is assembled in Tripoli, for a mission to capture Idrisi and as well reveal his source of money, Khalid, who transferred 5 million just before the team intervened. The team take custody of Khalid, but Omair eludes capture with help from his wife. Omair phones Mr. Ives, who is an arms dealer with the weapons for sale Omair intends to buy for the money.

Mac, Wyatt and the gang pursue Idrisi and his radicalized British wife. They seek to track him down via an arms dealer who just made a delivery to the cell leader, and was shot down by the same to get rid of loose ends. The crew from Section 20 rescues the arms dealer to find out what weapons he delivered and where Idrisi is. Later, when attacking Idrisi's compound, the US military gets involved, launching a bunker buster missile and putting the team in harms way.

El equipo se entera de la participación del Coronel Donovan en el Proyecto Tenebrae. Oleadas de soldados de PMC intentan recapturar a Idrisi en una batalla de correr, conducir y disparar contra la Sección 20. Donovan y Lowry tienen otro encuentro cara a cara.

The Russians are coming. Ives loses Idrisi to Russian agents. Twenty goes after the Atlas of covert British agents that Lowry stole and later hid. Stonebridge and Scott's surprise return aids Section 20 in a bold plan.